Figure 2

Characterization of AuNV conjugation process. (A) The absorbance spectra of the initial peptide AuNP conjugates. The full view shows the 400- to 800-nm range, and the zoom insert shows the peaks between 510 and 545 nm. Preconjugate refers to the carboxyl-PEG-AuNPs. The NH₂OH control refers to capping the active carboxyl groups on the particles with hydroxylamine. The preconjugates and NH₂OH control particles had the same peak, verifying that the conjugation protocol does not alter the absorbance peak. The particles conjugated with peptides show a 2-nm red shift. (B) TEM images of a 30-nm AuNP coated with PEG and a 30-nm gp100 AuNV. The surface of the peptide-coated AuNV appears rougher and thicker (red arrow) than the PEG-coated AuNP, indicating successful conjugation (scale bar = 10 nm).